Supercharger chirrup

My December 98 XKR is in amazing condition. Mechanically and visually.
55k genuine miles on the clock.

There is only one irritation.
On tick over up to just over 800 rpm there is a chirping noise which seems to be coming from inside the supercharger.
Above 800 rpm it goes away.
All pulleys belts etc have been checked, the oil changed in the supercharger itself.
The supercharger was stripped down a couple of years ago and found to be in perfect condition, where is this noise coming from?


Usually the BELT.
Spray some water on the belt as it rotates and listen for a change or temporary elimination of the noise?

The SQUEAK, SQUEAK usually occurs when the label passes by a tensioner or idler.

One of my XKRs does this for less than a minute at start-up but I don’t pay much attention to it.


Tried spraying water on the pulleys… No difference…

Tickover was running at around 6-700 rpm. Raised it to 800 rpm and the noise stopped.
Revved the motor and it was quiet. Let the engine go back to tick over and it was quiet.
Still wondering what was making the squeaking, chirruping sound.
Definitely in the supercharger body.
Engine only done 53 k

You might think it is coming from the supercharger but it could be coming from somewhere else.

If l put a piece of hollow pipe to my ear and place it on different parts of the engine, i.e. the cam covers the pulley bolts, the engine block, the squeak is loudest from the top of the supercharger housing.

Similar to using a stethoscope. May need a rebuild of the supercharger.